Suspension advice to improve highway confidence

[Todd15Fastback]

PM [MENTION=25806]SteedaTech[/MENTION] and he will walk you through the best choices for your needs.

Sponsored

 

[Doctor Fishtail]

Combine these tires (need 11" wheels) combined with BMR products and I can promise from my experience that you will be rid of your unstable at high speeds issues. https://www.tirerack.com/tires/tire...e&tireModel=Potenza+RE-11&partnum=23WR9RE11V2

 

[wildcatgoal]

Combine these tires (need 11" wheels) combined with BMR products and I can promise from my experience that you will be rid of your unstable at high speeds issues. https://www.tirerack.com/tires/tire...e&tireModel=Potenza+RE-11&partnum=23WR9RE11V2

325 RE-11s (or RE-11s of any OEM/similar size) are great track/HPDE tires but are impractical and unnecessary tires for a street vehicle (especially one that is daily-driven, without FI, and/or for anyone who isn't a lottery winner who can afford to replace tires often). Even my Conti DWS A/S tires made the car grip better than the stock Pirelli PZeros on the street. The new Firestone Indy 500s, MPSS, new Conti Sport tires... something that'll last with around the 300-340 TW rating range (I know, those ratings aren't uniform) is fine. Or the great A/S from Michelin if the OP wants A/S flexibility.

 

[Doctor Fishtail]

325 RE-11s (or RE-11s of any OEM/similar size) are great track/HPDE tires but are impractical and unnecessary tires for a street vehicle (especially one that is daily-driven, without FI, and/or for anyone who isn't a lottery winner who can afford to replace tires often).

This is a matter of opinion. Many guys in our local group would disagree. We are talking about unstable conditions at high speeds. This tire WILL help without a doubt combined with BMR products it will eliminate that unstable issue.

 

[wildcatgoal]

You're suggesting someone get 11" wide wheel and a 325 200TW tire (which is an entry level track tire) to drive around on the street with to solve instability. I suppose that'd help but it isn't necessary. I mean, I have an 11" wide wheel in the rear and a 10" wide wheel in the front wrapped with cheapo Cooper Zeon RS3-S 275 and 305 tires and, with my Steeda suspension, haven't had a lack of stability in about 20K miles. Or riding on the street with my square track setup (285/35-19) - no instability there, either. Or riding with stock PP wheels and stock size Conti DWS tires - no instability there, either.

Matter of fact, actually, RE-11s of any size 285-325 are indeed an extreme solution for the OP. If the OP can afford them, afford replacing them sooner than any regular summer tire, at alone A/S tires, okay. But there are, as exemplified above, more practical ways to approach tire selection in combination with suspension upgrades, especially for non-FI vehicles like the OP's.

RE-11s are great tires, we can agree on that at least. Glad you like yours. But knowing you have FI... well, 325 and RE-11 makes a lot more sense.

 

[SteedaTech]

Been enjoying my 2016 GT 6-spd (non-PP). This thing is a beast.

I drive mostly highway and enjoy the occasional on ramp WOT getaway merge. What I have noticed is as I get into the powerband I feel the car sit up and almost seems like it's tie toeing on the edge of loosing traction. I get the same feeling when downshifting and passing someone even on straight stretches of road. I have zero performance mods, completely stock.

Question for the forum brain trust:
There are a million different suspension option out there. I'm not looking to heavily modify my suspension, but what options are avlb to eliminate that feeling?

I want to be able to downshift, smash the gas, and not feel like I'm on the verge of losing traction.


Thanks in advance!

To get to your objectives faster, you can call me anytime @ 954-960-0774

Thanks Mike D

 

[Doctor Fishtail]

You're suggesting someone get 11" wide wheel and a 325 200TW tire (which is an entry level track tire) to drive around on the street with to solve instability. I suppose that'd help but it isn't necessary. I mean, I have an 11" wide wheel in the rear and a 10" wide wheel in the front wrapped with cheapo Cooper Zeon RS3-S 275 and 305 tires and, with my Steeda suspension, haven't had a lack of stability in about 20K miles. Or riding on the street with my square track setup (285/35-19) - no instability there, either. Or riding with stock PP wheels and stock size Conti DWS tires - no instability there, either.

Matter of fact, actually, RE-11s of any size 285-325 are indeed an extreme solution for the OP. If the OP can afford them, afford replacing them sooner than any regular summer tire, at alone A/S tires, okay. But there are, as exemplified above, more practical ways to approach tire selection in combination with suspension upgrades, especially for non-FI vehicles like the OP's.

RE-11s are great tires, we can agree on that at least. Glad you like yours. But knowing you have FI... well, 325 and RE-11 makes a lot more sense.

Think out of the box. They make RE-11s in smaller sizes as you posted. And agreed will help address his issue. But remember the shorter sidewall helps big time with the high speed stability. Combined with some BMR handling springs the OP will lose his mind with happiness. And BMRs prices cannot be beat. So let's look at the big picture here. BMRs over all experience over the competition combined with their quality engineering and best of all friendly pricing is phenomenal!!! :ford:

 

[NightmareMoon]

Sounds like the OP is talking about raw traction, not really stability.

First, the car does have 400+ HP, so if expectations have to be managed. In a low gear, its going to break loose sometimes (depending on the road surface). Tires will help, but you also have to learn some respect for the performance, and expecting the car to hook under all circumstances is unreasonable. If the steering wheel is turned much at all, and you mash the gas, its going to come around on you in most RWD sports cars, and the mustang has more power than most. Thank god for modern stability control systems.

Tires are the biggest single improvement for raw traction. Old tires get hard and loose grip as they age, so if he's on old Pirelli A/S, there is a ton of room for improvement.

Once you get tires, go ahead and get your alignment checked, in particular the rear toe angles (which have a big impact on stability when the rear tires are slipping). We all know tolerances from the factory are not so great.

 

[jbailer]

I didn't get the impression the OP was having an issue with pure traction, he said, "feel the car sit up and almost seems like it's tie toeing on the edge of loosing traction". It'd probably be best to get it from him but what it sounds like to me is nothing to do with traction itself, just the feeling that it may lose traction. That floaty feeling that the stock chassis has with all the slop. While wider tires definitely add some stability, it's not going to address that floaty, disconnected feeling the stock IRS has.

Sounds like the OP is talking about raw traction, not really stability.

First, the car does have 400+ HP, so if expectations have to be managed. In a low gear, its going to break loose sometimes (depending on the road surface). Tires will help, but you also have to learn some respect for the performance, and expecting the car to hook under all circumstances is unreasonable. If the steering wheel is turned much at all, and you mash the gas, its going to come around on you in most RWD sports cars, and the mustang has more power than most. Thank god for modern stability control systems.

Tires are the biggest single improvement for raw traction. Old tires get hard and loose grip as they age, so if he's on old Pirelli A/S, there is a ton of room for improvement.

Once you get tires, go ahead and get your alignment checked, in particular the rear toe angles (which have a big impact on stability when the rear tires are slipping). We all know tolerances from the factory are not so great.

 

[Augster]

Big thanks to everyone who has responded! It confirms I joined the right forum.

Going to try my best to answer some of the questions peppered in regarding my OP.

- Goal: maintain/slightly improve current ride feel and stabilize when accelerating at high speeds (75+), ex. Downshifting to 4th to pass shouldn’t be “risky”
- This is my daily driver (avg. 50 miles per day)
- I would like to track it for fun someday, but not the priority.
- Outside of wheel hop, no concerns regarding traction during low speeds. Completely agree and respect the power we have.
- Not interested in lowering ride height. I think the stock 20” wheels do a good job balancing the ride height look
- I plan on keeping the current 20” rims. Going to keep the PZeros until they are wasted and need replacement. Currently have 4500 miles on the odometers.
- I have had my eye on the BMR CB005 Cradle Lockout Kit to resolve wheel hop. I wasn’t sure if it would also help eliminate high speed stability as well. Sounds like it would.
- Prefer solutions I could install myself

 

[BmacIL]

Big thanks to everyone who has responded! It confirms I joined the right forum.

Going to try my best to answer some of the questions peppered in regarding my OP.

- Goal: maintain/slightly improve current ride feel and stabilize when accelerating at high speeds (75+), ex. Downshifting to 4th to pass shouldn’t be “risky”
- This is my daily driver (avg. 50 miles per day)
- I would like to track it for fun someday, but not the priority.
- Outside of wheel hop, no concerns regarding traction during low speeds. Completely agree and respect the power we have.
- Not interested in lowering ride height. I think the stock 20” wheels do a good job balancing the ride height look
- I plan on keeping the current 20” rims. Going to keep the PZeros until they are wasted and need replacement. Currently have 4500 miles on the odometers.
- I have had my eye on the BMR CB005 Cradle Lockout Kit to resolve wheel hop. I wasn’t sure if it would also help eliminate high speed stability as well. Sounds like it would.
- Prefer solutions I could install myself

That kit will work very well to cure what you're unhappy with (stability & hop). I'd also think about pairing your stock springs with some of the Steeda fixed-valve Pro-Actions to really get it planted without a degradation in ride (improved in many respects).

 

[LG23]

Big thanks to everyone who has responded! It confirms I joined the right forum.

Going to try my best to answer some of the questions peppered in regarding my OP.

- Goal: maintain/slightly improve current ride feel and stabilize when accelerating at high speeds (75+), ex. Downshifting to 4th to pass shouldn’t be “risky”
- This is my daily driver (avg. 50 miles per day)
- I would like to track it for fun someday, but not the priority.
- Outside of wheel hop, no concerns regarding traction during low speeds. Completely agree and respect the power we have.
- Not interested in lowering ride height. I think the stock 20” wheels do a good job balancing the ride height look
- I plan on keeping the current 20” rims. Going to keep the PZeros until they are wasted and need replacement. Currently have 4500 miles on the odometers.
- I have had my eye on the BMR CB005 Cradle Lockout Kit to resolve wheel hop. I wasn’t sure if it would also help eliminate high speed stability as well. Sounds like it would.
- Prefer solutions I could install myself

From what you describe you don't have an issue with traction. Springs would be my first suggestion so the car doesn't feel as "floaty" like you're decribing. I just installed springs and while ripping it on the highway I remember saying multiple times "damn this thing feels planted". The subframe bushings kit wouldn't hurt either because maybe some of the wheel hop is contributing. Obviously some braces and sway bar upgrades but it sounds like you mean straight-line and merging floaty feeling at highway speeds.

 

[West TX GT]

I also suspect it is the feeling of instability that is what is bothering you. I recommend the steeda dampers and quality springs. The car will feel like it "hugs" the road better and more controllable. Stickier tires can only help though.

 

[Augster]

Here is what I decided on & ordered... for now:
- BMR Lockout kit
- Steeda Alignment Kit for Rear Subframe for BMR CB005 Kit
- Steeda jacking rails (for convince)

I'm going to start with the above and see what happens from there.



Below I still have on the list & will depend on any ride improvements still needed:
- Steeda fixed damp/struts
- Steeda progressive springs, my issue is I really don't want to lower the car

 

[qtrracer]

Been working with IRS cars since 01. The early version had lots of problems including unbelievable axle tramp - crutches work but cause other issues such as ride quality degradation. My '16 GT-pp is light years ahead. Yes, there is some axle tramp but not nearly as bad as the early Cobra's. So far, most of the issues guys have described I've experienced but after time have adjusted driving style to this car. This has proven more acceptable than ride degradation from after market crutches.

I have no shifting or clutch pedal problems (no spring change/elimination). Minimal axle tramp on hard launch, especially with LC on or feathering the throttle/clutch. Even power shifting is easier with the stock shifter. Have any of you hit red-line at night and had the entire dash light-up "red"? Right after that occurs, the computer kills fuel. So, there is a split second that allows red-line but no fuel cut to get to the next gear. This takes practice. But, this thing is so much better than my Cobra, that while I have respect for that platform this one is way better.

Sponsored